The invention concerning an image forming device or an optical disk for forming a visible image such as a character or a picture on a data recording surface of a recording type optical disk capable of recording data such as a CD-R or a DVD-R or on an exclusive label surface provided in an opposite side to the data recording surface to which a special processing is applied has been hitherto disclosed (for instance, see Patent Documents 1 and 2). This technique employs a phenomenon that colors are different (visible ray characteristics change) between a part on which the data is recorded by applying a laser beam to the data recording layer (a coloring matter layer or a dye layer) of the optical disk and a part on which the data is not recorded. This technique is employed so that a visible image can be formed on the data recording surface of the optical disk or the label surface of the optical disk on which the coloring matter layer is formed.    Patent Document 1: JP-A-2004-355764    Patent Document 2: JP-A-2002-203321